The present invention relates to improving the airflow in a cleanroom by providing a constant downward airflow across the entire area of a cleanroom ceiling. More specifically, the present invention relates to a flush lighting system for a cleanroom, wherein filtered air is provided across the entire area of a cleanroom ceiling. Also, the present invention provides a unique method of installing and locking into place the filter banks within the ceiling system.
Recent designs of cleanroom environments have begun to incorporate flush lighting systems in the cleanroom ceilings. Traditionally, protruding lighting systems were utilized in cleanroom designs. However, these protruding lighting systems created several problems in cleanroom operation. First, protruding systems prevented easy reconfiguration of cleanroom equipment and layout, thereby inhibiting flexibility of cleanroom configuration. Second, the protruding systems interfered with the downward flow of filtered air over the entire area of the cleanroom ceiling. Therefore flush lighting systems were developed to aid in both flexibility of cleanroom design and minimization of air turbulence.
Generally, cleanrooms utilize many features to improve the air quality of its environment. Most applicable to the present invention is the constant downward flow of filtered air through the cleanroom into a raised floor assembly. Typically, air is drawn into a large chamber or plenums above groups of filters in modular fabricated assemblies in the ceiling of a cleanroom. The air is then pushed through filters which remove particulate matter from the air. The air then flows downwards through the cleanroom and into the grated raised floor assembly. The air in the cleanroom is thereby recirculated approximately every 5-10 seconds.
Cleanrooms are vital components of many manufacturing processes. For example, a cleanroom environment is necessary for semiconductor wafer processing techniques to minimize wafer contamination. As the size of critical dimensions of semiconductor circuits decreases, the air purity requirements in cleanroom environments will need to become even more stringent.
One source of impurities in present cleanroom environments is dead air channels which occur underneath lighting fixtures and ceiling grid supports. These areas do not move air downward through the cleanroom, but rather create turbulence which can cause impurities to travel to other areas within the cleanroom where they may impede optimal processing conditions. Most cleanroom ceiling systems do not include a manner to prevent these dead air channels.
Therefore, a system must be developed to reduce or eliminate dead air channels in cleanroom environments. One alternative currently utilized places a screen with beveled edges underneath the ceiling filters. The beveled edges of the screen aid in blowing filtered air across the space underneath light wells. Another alternative currently utilized incorporates holes in the sides of the walls which comprise the light well, thereby allowing some air to flow through the light well. Both of these current systems permit some airflow underneath light wells. However, these alternatives do not provide a dedicated source of filtered air to the light wells, thereby permitting continuous downward, lamar airflow across the entire area of a cleanroom ceiling. It would therefore be desirable to develop a system which enables filtered air to flow downward through the light well itself.
Another problem in the prior art relates to the methods utilized in adjoining modular members of a ceiling system. Most systems require that adjacent modular members first be placed within a sealing relation to each other, for example, by lifting an adjacent member to a position next to its complementary member. Then, most systems require the user to utilize some type of mechanical adapter, such as a clamp, to lock the modules into position. Alternately, some system adhesively attach filters within plenum assemblies. However, given the potential size of modular units, these methods are cumbersome. It would therefore be desirable to develop a system which, upon lifting an adjacent member into position, it becomes automatically locked into place without the need for a second step.